YV12T25 Datasheet, PDF (7/12 Pages) Power-One – YV12T25 DC-DC Converter

YV12T25 DC-DC Converter
10 - 14 VDC Input; 0.8 - 5.5 VDC Programmable @ 25 A
Characterization
General Information
The converter has been characterized for many
operational aspects, to include thermal derating
(maximum load current as a function of ambient
temperature and airflow) for vertical and horizontal
mountings, efficiency, startup and shutdown
parameters, output ripple and noise, transient
response to load step-change, overload, and short
circuit.
The following pages contain specific plots or
waveforms associated with the converter. Additional
comments for specific data are provided below.
Test Conditions
All data presented were taken with the converter
soldered to a test board, specifically a 0.060” thick
printed wiring board (PWB) with four layers. The top
and bottom layers were not metalized. The two inner
layers, comprised of two-ounce copper, were used to
provide traces for connectivity to the converter.
The lack of metalization on the outer layers as well
as the limited thermal connection ensured that heat
transfer from the converter to the PWB was
minimized. This provides a worst-case but consistent
scenario for thermal derating purposes.
All measurements requiring airflow were made in the
vertical and horizontal wind tunnels using Infrared
(IR) thermography and thermocouples for
thermometry.
Ensuring components on the converter do not
exceed their ratings is important to maintaining high
reliability. If one anticipates operating the converter
at or close to the maximum loads specified in the
derating curves, it is prudent to check actual
operating temperatures in the application.
Thermographic imaging is preferable; if this
capability is not available, then thermocouples may
be used. The use of AWG #40 gauge thermocouples
is recommended to ensure measurement accuracy.
Careful routing of the thermocouple leads will further
minimize measurement error. Refer to Fig. D for the
optimum measuring thermocouple location.
Thermal Derating
Load current vs. ambient temperature and airflow
rates are given in Figures 13 to 16 for maximum
temperature of 110 °C. Ambient temperature was
varied between 25 °C and 85 °C, with airflow rates
from 30 to 400 LFM (0.15 m/s to 2.0 m/s), and
vertical and horizontal converter mountings. The
.
Data Sheet
airflow during the testing is parallel to the long axis of
the converter.
Fig. D: Location of the thermocouples for thermal testing.
For each set of conditions, the maximum load
current is defined as the lowest of:
(i) The output current at which any MOSFET
temperature does not exceed a maximum
specified temperature (110 °C) as indicated by the
thermographic image, or
(ii) The maximum current rating of the converter
During normal operation, derating curves with
maximum FET temperature less than or equal to
110°C should not be exceeded. Temperature on the
MOSFET at the thermocouple location shown in Fig.
D should not exceed 110 °C in order to operate
inside the derating curves.
Efficiency
Figures 1 to 6 shows the efficiency vs. load current
plot for ambient temperature of 25 ºC and input
voltages of 10.8 V, 12 V, and 13.2 V.
Ripple and Noise
The output voltage ripple waveform is measured at
full rated load current. Note that all output voltage
waveforms are measured across a 1 μF ceramic
capacitor. The output voltage ripple and input
reflected ripple current waveforms are obtained
using the test setup shown in Fig. E.
i_s
1 uH
Source
Inductance
Cin=150uF
Vsource
Tantalum
Capacitor
VIN
VOUT
Module
Cout = 1uF
Ceramic VOUT
Capacitor
GND
Fig. E: Test setup for measuring input reflected-ripple
currents, is and output voltage ripple.
ZD-01983 Rev. 2.1, 25-Jun-10
www.power-one.com
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